- Who should be treated?
- How is treatment of obesity and overweight
beneficial?
- Assessment of the obese or overweight individual.
- What are the goals of treatment?
- What are the treatment options?
Who should be treated?
All adults > 18years of age with BMI > 25kg/m2
are considered at risk. Treatment of overweight
is recommended only when patients have two or
more risk factors or a high waist circumference.
Assessment of a patient's absolute risk status
requires examination for the presence of associated
disease conditions.
Patients with following conditions are classified
as being at very high risk for disease complications
and mortality.
- Established coronary heart disease (CHD),
- Other atherosclerotic diseases,
- Type 2 diabetes, and
- Sleep apnea.
How is treatment of obesity
and overweight beneficial?
Obesity and overweight are associated with increased
morbidity and mortality. There is strong evidence
that weight loss in overweight and obese individuals
reduces risk factors for many diseases.
Weight loss is beneficial as it-
- reduces blood pressure in hypertensive individuals
- reduces serum triglycerides
- increases high-density lipoprotein (HDL)-cholesterol
- reduces total serum cholesterol
- reduces low-density lipoprotein (LDL)-cholesterol
- reduces blood glucose levels
Assessment of the obese or
overweight individual
When assessing a patient for risk status and as
a candidate for weight loss therapy, patient's
BMI, waist circumference, and overall risk status
should be taken into account. Patient's motivation
to lose weight should also be considered. Any
previous attempt at weight loss should be reviewed.
Patient's understanding of the complications of
obesity should be considered.
What are the goals of treatment?
The general goals of weight loss and management
are:
- to prevent further weight gain
- to reduce body weight, and
- to maintain a lower body weight over the long
term.
The initial goal of weight loss is to reduce body
weight by ten percent in 6 months of therapy.
It has been studied that a decrease of 300 to
500 kcal/day, results in weight loss of about
1/2 to 1 lb/week, that is ten percent reduction
in 6 months, in overweight patients with BMI in
the range of 27 to 35.
For more severely obese patients with BMI >
35, deficits of up to 500 to 1,000 kcal/day will
lead to weight loss of about 1 to 2 lb/week and
a 10 percent weight loss in 6 months.
After 6 months the rate of weight loss reduces.
In fact it may become stable inspite of therapy
because a lesser energy expenditure at the lower
weight.
Weight maintenance program consisting of dietary
therapy, physical activity, and behaviour therapy
should be continued indefinitely otherwise weight
is usually regained.
After 6 months if more weight loss is needed
then another attempt at weight reduction should
be made. This requires further adjustment of the
diet, physical activity and pharmacotherapy.
What are the treatments options?
1. Dietary therapy
Diet should be individually planned, taking into
account the patient's overweight status. The patient
must remain on low calorie diet (LCD) for a long
time otherwise weight is regained.
Diet must be nutritionally adequate. Depending
on the BMI, a reduction in total calorie by 300
to 1,000 kcal/day is required to achieve 10 percent
reduction in weight in 6 months.
Reducing dietary fat, along with reducing dietary
carbohydrates, usually will be needed to produce
the caloric deficit needed for an acceptable weight
loss. Besides decreasing saturated fat, total
fats should be 30 percent or less of total calories.
To minimise nitrogen loss the diet should contain
at least 0.8 to 1.2gm of protein per kilogram
of desired body weight. Food high in fibre should
be used as it is low in calorie content. Refined
sugars should be minimised as these provide calories
without any vitamins or minerals.
Very low calorie diets (VLCD) - These limit daily
intake to 300-700 cal/day. Some diets are limited
to proteins and are called protein supplemental
modified fasts (PSMF). The weight reduction is
rapid with these diets but they can have serious
side effects like orthostatic hypotension, fatigue
cold intolerance, dry skin, hair loss and menstrual
irregularities in women. Crash diets are often
ineffective.
2. Physical activity
Most of the weight loss occurs because of decreased
caloric intake but increase in physical activity
is important for prevention of weight regain.
In addition to maintenance of reduced weight it
benefits by reducing cardiovascular and diabetes
risks beyond that produced by weight reduction
alone.
Obese patients are generally inactive, they should
be encouraged to increase activity. Exercise should
be started gradually and increased over a period
of time. The patient can begin with simple exercise
like walking. The exercise can be done all at
one time or intermittently over the day. All adults
should engage in at least 30 minutes or more of
moderate-intensity physical activity everyday.
Moderate exercise does not increase food intake
in obese as it does in lean individuals. Therefore
it is helpful in induction and maintenance of
weight loss.
3. Behaviour modification
In behaviour modification the obese patient should
be first made aware of what and how much he or
she eats, as many times a person eats without
giving a thought to the calorie content of the
food. Patient should be educated to monitor the
quantity of food eaten and when, where, with whom,
it is eaten. All this should be analysed and discussed
with the patient.
New modes of eating are suggested to the individual,
like, not eating between meals, eating slowly,
watching the portion eaten etc. The aim is to
reduce food intake.
Behaviour change includes increased physical
activity. Behavior modification also strives at
stimulus control, cognitive restructuring and
environmental management. This therapy is usually
done in groups.
4. Phamacotherapy
Available evidence indicates that certain drugs
can augment the benefits of LCD, physical activity,
and behaviour therapy in weight loss. There is
general agreement that drug therapy should be
used in patients with a BMI of >= 30 with no
concomitant risk factors or diseases, and in patients
with a BMI of >= 27 with concomitant risk factors
or diseases.
Drugs for obesity treatment should be prescribed
only to patients who understand that life-long
vigilance towards diet and physical activity is
required for sustained weight loss. Continual
assessment of the patient by the physician for
efficacy and safety of the drug is essential.
The drugs that have shown efficacy in management
of obesity and are available for use are as follows:
(a) Anorexiant drugs:
These drugs reduce appetite by acting centrally
through the brain neurotransmitter pathways. Weight
loss with these is rapid initially but then it
reaches a plateau, probably due to the limit of
their therapeutic effect. They are generally used
for maintainance of weight loss.
Potential for abuse, tolerance and adverse effects
like increased risk of pulmonary hypertension
should be considered before use of these compounds.
Fenfluramine hydrochloride and combination have
been taken off the market after studies showing
their association with cardiac valvulopathy. Among
the available anorexiants, Phentermine (resin)
has demonstrated efficacy in long term placebo
controlled trials.
(b) Sibutramine:
It is a serotonin and noradrenaline reuptake inhibitor
that increases energy expenditure and satiety.
Its weight loss effects are primarily mediated
by its noradrenaline action because pure selective
seretonin reuptake inhibitors have not been shown
to produce long-term weight loss.
Several studies have demonstrated that Sibutramine
enhances weight loss modestly and helps facilitate
weight loss maintenance. It is generally well
tolerated. However, there is a marginal increase
in heart rate and blood pressure with its use.
(c) Orlistat:
This drug acts by inhibiting pancreatic lipase
and thus reducing absorption of fat in the intestine.
Side effects include steatorrhoea, loose, frequent
stools, fecal urgency and fecal incontinence.
Fat-soluble vitamins need to be suplpemented as
there is partial malabsorption.
5. Surgery for weight
reduction
Surgery for weight reduction is indicated in patients
with clinically severe obesity, i.e., BMI >=
40 or >= 35 with comorbid conditions. It is
reserved for patients in whom pharmacotherapy
has failed to achieve weight loss and who are
suffering from the complications of extreme obesity.
The surgical options are gastric restriction
(vertical gastric banding) or gastric bypass (Roux-en
Y). Guidance on diet and physical activity prior
to and after the surgery is important to achieve
benefit. Behavioural and social support should
be provided to the patient.
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